| 摘要 |
<p>A method of increasing the purity of ultrapure water, in which any impurities contained in ultrapure water can be stably removed to a high degree within a limited space over a prolonged period of time; and an apparatus therefor. Ultrapure water introduced in ultrapure water purity increasing apparatus (10) passes through ion exchange resin layer (5) within inferior compartment (1a). In this stage, metal ions, etc. contained in the ultrapure water are removed by the ion exchange resin. Thereafter, the ultrapure water passes through perforated plate (4), flows into superior compartment (1b) and permeates ion exchange filter (6). In this stage, any metal ions, etc. remaining unremoved by the ion exchange resin layer (5) are removed. That is, metal ions are removed to a certain extent by the ion exchange resin, so that it is satisfactory for the ion exchange filter provided downstream thereof to remove an extremely small amount of metal ions. Consequently, reaching of the ion exchange filter to breakthrough within a short period of time can be prevented, thereby attaining increasing of the purity of ultrapure water over a prolonged period of time.</p> |
